Process of making solutions of cuprammonium hydroxid.



V nmrnn fsrArns rArnNr orr c-E;

innnnnr LECOEUR, or Room, rnnncn, ASSIGNOR 'ro socmrn momma LE cnmoin,

OF ROUEN, FRANCE, A. CORPORATION OF FRANCE.

PROCESS OF MAKING SOLUTIONS OF CUPRAlVIMONIU'M HYDROXID.

No Drawing.

Specification of Letters Patent. Patented J an. 25, 1910. Applicationfiled January 12, 1909. SerialINb. 471,984.

To all whom it may concern:

Be it known that I, Aldenn'r LEO0EUR,- a citizen of the Republic ofFrance, residing at Reuen, France, have invented certain new and usefulImprovements in the Process of Making 'Solutions of CuprammoniumHydroxid, of which the following is'a" specification.

The present invention relates to the 1preparation in the. manufacture ofeel ulose threads or filaments, of solutions of colloidal hydratedcuprammonium o xid which dissolve definite and easily regulatedproportionsof cellulose, according to the density and solidity of thethreads or filaments of cellulose which it is desired to obtain from thespinning fluid.

As already described in my Patent No. 863,801, the solutions ofcolloidal hydrated cu rammonium oxid purified by dialysis yie d uniformviscous solutions of cellulose which can be kept at ordinarytemperatures. l have now discovered that when the whole of the hydratedcuprammonium oXid is in a colloidal state, the amount of cellulose whichcan be dissolved by the solution is proportional to the copper present,allthe copper present. being in an active state. The ro ortion ofcellulose which may be disso ve by solutions of the requisite degree ofbasicity is about two parts by weight of cellulose to one of cupric oxidin solution.

Solutions of colloidal hydrated cupranr monium oxid may be prepared forinstance either by treating solutions of sulfate of copper or othersalts of copper with ammonia and caustic alkalies with subsequentdialysis. call this liquor A. (Jr by the simultaneous action of air andammonia on metallic copper with subsequent dialysis of the solution, asdescribed in my Patent No. 863,802. I call the solution thus obtained liuor B. I have foundhowever that if so utions, of colloidal hydratedcuprammonium oxid prepared by the former method are beyond a certainconcentration, they certain compounds, probably of sodium, which cannotbe removed by filtration or dialysis, and the presence of which causesthe thread to break easily and lessens its luster. Thus although it ispossible to prepart by weight pare solutions of colloidal hydratedcuprammonium ,oxid' by this method containing as much as 30 grams copperper liter,

in consequence of the above impurities, Iv

have found it impracticable for the spinning of cellulose threads toemploy a solution containing more than 12 grams copper or 15 gramscupric oxid prepared by this method, even in the cold. A solution ofthis strength is however only capable of dissolving 3O grs. celluloseper liter, even when all the copper is in the form of colloidal hydratedcuprammonium oxid, and this proportion of cellulose is too small forspinning threads of suflicient solidity.

According to the present invention a liquor A of greater strength, whichis comparatively cheap to manufacture, may be employed with technicallyuseful results if mixed with liquor B in such proportions 7 that theresulting mixture contains about 25 grs. or upward per liter of activecopper, i. e. in the state of colloidal hydrate cuprammonium oxid, butof which no more than about 12 grs. copper per liter is de rived fromliquor A. As liquor B can be prepared of much greater strength,containing 25 to 45 re. active copper per liter, free from the" aove-mentioned impurities in liquor A, and capable of dissolvingllO oreven 120 grs. of cellulose per liter, a suitable spinning fluidcontaining for example 80 or 90 grs. cellulose per liter in solution,can be prepared by the admixture of the cheaper liquor A with liquor Bin suitable proportions. I

l have further found that by combining the two liquors for thepreparation of the cellulose solvent it is possible to obtain asubstantially better and more perfectly cois effectedby the-combinationof the solutions as explained. The lower proportion of ammonia likewiseenables a less c011- centrated preci itating bath to be employed.

The liquor K may be prepared for example by treating a solution ofcopper sulfate (one molecule) with caust1c soda (2 molecules in theresence ofammonia (2 molecules; in sufiiclently dilute solution, so thatafter removal of the black partlcles of anhydrous cuprous oxid and thecrystallizable cuprammonium oxid b filtration and dialysis, the.resulting solut1on of colloldal cuprammonium oxid does not contain morecopper in solution than will belequrvalent to 12 grs. copper or 15 grs.cupric oxid per liter of the required mixture of liquor A and liquor B.

The liquor B is repared as described 1n my U. S. Patent 0. 863,802 bypassing a current of air deprived of carbonic acid through copperturnings suspended in a solution of ammonia preferably of low density,suflicient caustic soda being added to neutralize the nitrous acidformed. The operation is stopped when the concentration of the colloidalhydrated cuprammonium oxid is suflicient to dissolve a given quantity ofcellulose when added to liquor A; the solution is then submitted todlalysis to remove the impurities it still contains.

Ewample of the preparaton of a cuprammoniaoal Solution to dissolve .90grs. cellulose per liteva-Mix 400 cc. liquor A contaming colloidalhydrated cuprammonium ox1d equivalent to 15 grs. cupric oxid or' 12 grs.copper, which is capable of dissolving 30 rs. cellulose with 600 cc.liquor B, containmg colloidal hydrated cuprammonium oxid equivalent to30 grs. cu ric oxid or grs. copper, which is cap'ab e of dissolvmg 60rs. cellulose. These proportions are given y way of example and may bevaried according to the quality of the thread it 1s desired tomanufacture. For instance it 1s found that with a solution prepared inthis manner containing 60 rs. ce lulose per liter, supple and silkythrea s of extreme fineness may be manufactured, but for threads ofgreater density solutions containing 80, 90 or 100 grs. cellulose perliter are employed.

Instead of reparmg the solutions independently be ore effecting theadmixture, as in the above example, it is of course obvious that aliquor B may be first and the liquor A to be combined t erewith may beprepared direct therein, the excess of ammonia in liquor B serving toform a certain part of the cuprammonium oxid of the liquor A.

The dialysis of the solutions can of course be performed before or afterthe mixing.

The cellulose must be submitted to the action of the solvent in a purestate, whether 'ment of a solution of sulfate 0 repared.

derived from cotton waste, wood-pul or other source, and it musttherefore un ergo preliminary treatment for eliminating thenon-cellulose products and transforming the mass of cellulose substanceinto soluble orthoor normal cellulose (see Fremys classification,Oomptes Rendus .83, pa e 1136) adapted for dissolving in co per iquorand producing under suitable p ysical and mechanical conditions abrilliant, su ple and resistanltdthread. The solution ta es place in theco What I claim and desire to secure by Letters Patent is:

1. The process of making solutions of cuprammonium hydroxid, comprisintreatment' of a solution of a copper sa t with ammonia and causticalkali, and treatment of metallic copper with air and ammonia inpresence of water, the solutions being comined and being dialyzed,substantially as described.

2. The process of making solutions of cuprammonium hydroxid, comprisingtreatcopper with ammonia and caustic alkali, and treatment of metalliccopper with air and ammonia in resence of water, the solutions being comined and being dialyzed, substantially as described.

3. The process of making solutions of cuprammonium hydroxid, comprisingreparation of a solution of collo1dal hydrated cuprammonium oxid bytreating a solution of a copper salt, as coliper sulfate, with ammoniaand caustic a ali, and preparation of a solution of colloidal hydratedcuprammonium oxid containing a substantially greater quantity of activecopper by treatmg meta ic copper with air and ammonia in presence ofwater, said solutions being mixed and being dialyzed, substantially asdescribed. 4. The process of making solutions of cuprammonium hydroxid,comprising reparation of a solution of colloldal hydrated cuprammoniumoxid rich in ammonia by treating metallic copper with air and ammonia inpresence of water, and the pre aration therein of a solution of collo1dahydrated cuprammonium oxid by treatment of a copfifr salt, as coppersulfate, with caustic a ali and ammonia, whereb the surplus ammonia ofthe first mentione solution is utilized for the preparation of thesecond solution the solutions being mixed and being dialyzed,substantially as described.

5. A .process of making solutions of cuprammonium hydroxid, comprisingtreatment of a solution of a copper salt, with ammonia and causticalkali, and treatment of metallic cofpper with air and ammonia inpresence 0 water, the solutions being dialyzed andbeing combined tocontain twentyfive grams and upward of copper per liter in the state ofcolloidal hydrated cuprammonium oxid whereof not more than twelve gramscopper per liter is obtained by the treatment of the copper salt insolution with ammonia and caustic alkali.

In witness whereof, I have hereunto signed my name inthe presence of twosubscribing witnesses.

ALBERT LECOEUR. Witnesses:

PAUL RUDoLF, E. M. J. DELLEPLANE.

